fix: allow a minimum retry wait of 0 ms

openfga_sdk/api_client.py

@@ -38,6 +38,9 @@ def random_time(loop_count, min_wait_in_ms) -> float:
     """
     minimum = math.ceil(2**loop_count * min_wait_in_ms)
     maximum = math.ceil(2 ** (loop_count + 1) * min_wait_in_ms)
+    # randrange() raises on an empty range, e.g. when min_wait_in_ms is 0
+    if maximum <= minimum:
+        return minimum / 1000
     return random.randrange(minimum, maximum) / 1000
 
 

openfga_sdk/oauth2_common.py

@@ -19,7 +19,11 @@ def jitter(loop_count, min_wait_in_ms):
     """
     minimum = math.ceil(2**loop_count * min_wait_in_ms)
     maximum = math.ceil(2 ** (loop_count + 1) * min_wait_in_ms)
-    jitter = random.randrange(minimum, maximum) / 1000
+    # randrange() raises on an empty range, e.g. when min_wait_in_ms is 0
+    if maximum <= minimum:
+        jitter = minimum / 1000
+    else:
+        jitter = random.randrange(minimum, maximum) / 1000
 
     # If running in pytest, set jitter to 0 to speed up tests
     if "pytest" in sys.modules:

openfga_sdk/sync/api_client.py

@@ -37,6 +37,9 @@ def random_time(loop_count, min_wait_in_ms) -> float:
     """
     minimum = math.ceil(2**loop_count * min_wait_in_ms)
     maximum = math.ceil(2 ** (loop_count + 1) * min_wait_in_ms)
+    # randrange() raises on an empty range, e.g. when min_wait_in_ms is 0
+    if maximum <= minimum:
+        return minimum / 1000
     return random.randrange(minimum, maximum) / 1000
 
 

test/backoff_test.py

@@ -0,0 +1,29 @@
+import unittest
+
+from openfga_sdk import api_client
+from openfga_sdk.oauth2_common import jitter
+from openfga_sdk.sync import api_client as sync_api_client
+
+
+class TestBackoff(unittest.TestCase):
+    """The retry wait helpers accept a minimum wait of 0"""
+
+    def test_random_time_with_zero_min_wait(self):
+        for loop_count in range(3):
+            self.assertEqual(api_client.random_time(loop_count, 0), 0)
+            self.assertEqual(sync_api_client.random_time(loop_count, 0), 0)
+
+    def test_random_time_stays_in_range(self):
+        for loop_count in range(3):
+            for random_time in (api_client.random_time, sync_api_client.random_time):
+                wait = random_time(loop_count, 100)
+                self.assertGreaterEqual(wait, 2**loop_count * 100 / 1000)
+                self.assertLess(wait, 2 ** (loop_count + 1) * 100 / 1000)
+
+    def test_jitter_with_zero_min_wait(self):
+        for loop_count in range(3):
+            self.assertEqual(jitter(loop_count, 0), 0)
+
+
+if __name__ == "__main__":
+    unittest.main()